Alright, I have 350 sbc in a 90 camaro, did a t56 from the original 700r....I tightened everything up took it out, shifts fine...only thing is it feels like the transmission is slightly rocking back and forth...it always engages into gear but some times its harder then others. Its always jerking when I'm shifting at cruising speed...I'm very cautious with it cause I don't know what's causing is...I checked the trans mount its fine...I don't know where else to look????

are your motor mount shot.. the shifter will move with the tranny as it torques over.. this is normal.. shot motor mounts can make this movement bigger.. so can a junk tranny mount.. reblead the master and slave.. it shouldn't be hard to shift..unless the hole you cut into the floor isn't big enough. and the shifter is up against the floor when the engine torques over.. start by rechecking all your bolts.. if the motor mounts are the originals, they are junk.. replace them.. same with the tranny mount..
where are you getting the info that the 3rd gen torque arm and 4th gen arm are the same and the tranny crossmemer mounting spot in the unitbody is the same.. I'd double check this before you twist your car.. 3rd gen is steel the 4th gen is alum..